The present invention relates to a method for accommodating a magnetic tape cassette in a cassette storage case, and also to an index card for use in a cassette storage case, particularly such a method and index card used with a book-case type cassette storage case for a video tape cassette.
Audio or video magnetic tape cassettes are, in general, kept in a cassette storage case when not in use. The cassette storage case is used to protect the cassette from external shocks and to prevent the entrance of dust into the cassette. Particularly in the case of a high density magnetic recording tape employed for an audio or video signal recording operation, it is essential to prevent the entrance of dust into the cassette because the adherence of dust to the tape may cause troubles such as signal dropout.
Examples of a cassette storage case of this type include a plastic case formed by injection molding having a lid with a pocket into which the cassette is inserted and a casing coupled pivotally to the lid so as to be swingable like a door, and a so-called "book-case" type cassette storage case formed, for instance, by first forming a plate having a predetermined configuration by blanking, and bending and assembling the resin plate thus formed using an adhesive. The book-case type cassette storage case is superior to the ordinary plastic case in that the width in the direction of cassette thickness can be reduced.
The cassette storage case is provided with an index card which necessary data relating to the recorded content of the cassette stored therein can be recorded. The index card is constructed as indicated at 14 in FIG. 11, and is placed in the case as shown in FIG. 10.
The index card 14 set in the book-case type cassette storage case 3 is by bending the index card 14 along a bending line 16 in one end portion so that the resultant index card is L-shaped in section with an erect wall 15. The erect wall 15 is to be set on the inner surface of the rear wall of the cassette storage case 3. Therefore, necessary data such as a title recorded on the erect wall 15 can be read through the transparent rear wall of the cassette storage case 3.
The reason for the employment of the index card 14 bent in such a manner that it is L-shaped in section is as follows: If the index card were bent in such a manner that it is U-shaped in section, that is, if it is so bent that it is brought in contact with the inner surface 3b of the bottom wall, the inner surfaces 3a of the rear wall, and the inner surface 3c of the top wall of the cassette storage case 3, then the index card will cover the top window of the magnetic tape cassette 4, thus making it impossible to visually detect the amount of tape remaining in the cassette.
The index card may be formed by bending one end portion of the index card in such a manner that it is U-shaped in section as in the case of an index card provided for a compact cassette tape storage case. However, the index card thus formed is disadvantageous in the case where a magnetic tape cassette to be stored in the cassette storage case has an upper lid, as in the case of an 8-mm video tape cassette. That is, the front edge of the bent portion of the index card, since it extends in the widthwise direction of the inner surface 3c of the top wall of the cassette, is liable to be caught by the upper lid, thus making it rather difficult to insert the cassette into the case.
In the index card 14 bent along the bending line 16 in its one end portion in such a manner that it is L-shaped in section, the distance w.sub.2 between the bending line 16 and the edge is made shorter than the height H.sub.1 of the space in the cassette storage case, that is, the height h.sub.2 of the erect wall 15 is made shorter than the height H.sub.1 of the space in the cassette storage case 3, whereby the index card 14 can be inserted into the cassette storage case 3 with ease. Hence, the index card 14 in the cassette storage case 3 applies no force to the inner surfaces of the case 3. As a result, when no magnetic tape cassette 4 is in the cassette storage case, the index card 14 is liable to slip down in the case.
In the case of the index card whose one end portion is bent U-shaped in section as in the case of a compact cassette tape accommodating case, the force of opening the bent portion of the index card acts on the inner surfaces of the cassette storage case in the direction of thickness of the latter at all times. Hence, even after the magnetic tape cassette has been extracted from the case, the frictional force between the index card and the inner surfaces prevents the index card from falling out of the case. On the other hand, the above-described index card 14 applies no force to the inner walls of the case, and therefore it can drop out of the case readily when the magnetic tape cassette 4 is extracted from the case.
On the other hand, the cassette storage case 3 suffers from difficulties in that, since its cassette inserting opening is open at all times, dust can easily enter the case, and the magnetic tape cassette can fall out of the case when the case is being handled and can thus be damaged.